Electric weft detecting system for looms



March 27, 1951 v, SEPAVlCH 2,546,617

ELECTRIC WEFT DETECTING SYSTEM FOR LOOMS Filed Dec. 2'7, 1948 J/ FIG.I

s5 B il9 l I 22 2s INVENTOR F I G 2 VICTOR E SEPA V/Gh' ATTORNEYPatented Mar. 27, 1951 UNITED STATES PATENT OFFICE ELECTRIC WEFTDETECTING SYSTEM FOR LOOMS Application December 27, 1948, Serial No.67,339

This invention relates to electric weft detecting systems for looms andit is the general object of the invention to provide such a system withcircuits which will energize the loom controlling electromagneticdevice, such as a solenoid, for a short part only of the time elapsingbetween its energization and the time at which the loom uses the controlexercised or indicated by the device.

Electric weft detecting systems for stopping looms generally employ someform of feeler or detector and a solenoid which positions one part ofthe loom, such as a knock-off mechanism, for operation by another partthereof. There is ordinarily an appreciable interval of time betweenindication of weft exhaustion by the weft detector and operation of thisother part to effect a change in loom operation, such as loom stoppage.In electric weft detecting systems commonly used the solenoid isrequired to be energized throughout this entire period of time andbecause of this fact it has been necessary to use a solenoid large andexpensive enough to withstand continued energization, even though abrief momentary energization is all that is required.

It is an important object of the present invention to provide anelectric detecting system which includes a normally charged electriccondenser for energization of the solenoid and means for discharging thecondenser through the solenoid incident to indication of weftexhaustion. The solenoid is therefore energized for the brief intervalof time only during which the condenser discharges.

A type of electric weft detector which has gone into general use employsa pair of detector fingers or prongs for engagement with a denudedmetallic ferrule on the bobbin of a depleted weft shuttle. It has beenfound that these detector fingers are likely to rebound when they arestruck by the metal ferrule so that the total amount of time duringwhich the detecting circuit can be closed is materially less than thatfraction of the cycle of the loom during which the fingers would contactthe ferrule if there wer no rebounding. The amount of electric powerwhich would otherwise pass through the detecting circuit is thereforereduced to an amount insufficient to operate arelay or the like and alsocharge a condenser.

It is a still further object of the invention to employ a normallyclosed charging circuit for the condenser and a relay responsive to verysmall currents which when energized by momentary closure of the detectorcircuit will connect the condenser to a discharge circuit including the5 Claims. 01. 139370) solenoid andsimultaneously open the chargingcircuit so that current from a primary source, such as a transformer,cannot flow through the solenoid.

With these and other objects in view which will appear as thedescription proceeds, the invention resides in the combination andarrangement of parts hereinafter described and set forth.

In the accompanying drawings, wherein a convenient embodiment of theinvention is set forth,-

Fig. 1 is a diagram of the electric circuits forming the subject matterof the present invention in their normal condition prior to indicationof weft exhaustion, and

Fig. 2 is a View similar to Fig. 1 but showing the conditions whichexist when the weft detector indicates Weft exhaustion.

- The invention is applicable to various types of' electromagnetic loomcontrol systems not necessarily limited to stopping mechanisms, but isshown herein as applied to such a mechanism for the purpose of stoppingloom operation upon exhaustion 0f weft. The stopping of the loom may beeffected by means shown, for instance, in prior patents to Payne Nos.1,873,465 and 2,266,474. The knock-off mechanism employs a cam l0 whichmay be on the bottom or two pick shaft of the loom to rock an actuatorlever l I periodically during loom operation, usually at two-pickintervals. A knock-01f or stopping lever I2 is normally in non-stoppingposition during loom operation and has attached thereto a link l3 whichis ordinarily in the down or non-stopping position thereof due to thefact that a solenoid S is normally deenergized and its core I4 is in lowposition. During normal running conditions the cam causes the lever H tohave periodic work ing strokes to the left, but the link 13 will be downout of the path of the lever so that the stopping lever I2 will remainunchanged. If the solenoid is energized its core I4 is lifted to raisethe link to stopping position. in the path of lever ll, whereupon thelever I2 is moved from non-' stopping position to stopping or knock-01fposition to effect loom stoppage.

A weighted lock or holding detent I5 under turns to the right the detentis returned to its 7 normal non-supporting inclined position. For

further details of the detent reference may be had to the aforesaidPayne patents.

Detection of the condition of weft in the shuttle ordinarily occurs whenthe lay is at front center, but the cam I6 is usually set so that itwill initiate loom stoppage later in the loom cycle and at a time whichwill permit complete loom stoppage before the next picking operation,which ordinarily occurs when the lay is at top center. There istherefore an appreciable interval of time lapsing between indication ofweft exhaustion by the Weft detector and movement of the link by leverII. In the past the solenoid S has been maintained energized throughoutthis interval and because of this fact it has been necessary to employ asolenoid which could withstand continued energization.

The weft detector D employs right and left detector fingers l"! and I8for cooperation with the metallic ferrule l9 on bobbin B. The bobbin ispresented to. the detector by forward movement of th lay andwhen theferrule is covered .with weftthe detector fingers fl and .I8 areinsulated fromeach other; butwhen weft exhaustion occurs the ferrule isuncoveredand electrically connects the fingers; These fingers areordinarily maintained in their normal rearward position by springs(notshown) which yield as: the fingers move forwardly.

When the metal ferrul strikes 'the'finger the latteriare likely torebound, each detector, finger rebounding in a manner determined partlyat east by its own spring; The rebounding of the, detector fingers islikelyto'be unequal'and one' finger may return to contact with theferrule andstart a second rebound while the other finger due to itsrebounding is still out of contact with the ferrule. flow through thedetector for the period at least during which the fingers. fl andl8,rebound and are not .in simultaneous engagement with the ferrule. Ifthe solenoid'is directly energized by the detector circuitthisrebounding may prevent its full energization and it is for thisreason that a relay is employed which can be energized'by a much smallercurrent than would be required by the solenoid, this relay being inthecircuit of the detector and effectiv to establish contacts which controlthe circuits, associated with the solenoid when the detector indicatesweft'exhaustion;

As-sliown for instance in Fig. 1, a transformer T supplying alternatingelectric current has leading therefrom line' wires- 20 and 2i, thelatter being electrically connected by wire-22 to the detector fingeri8. Finger I! is connected electrically by wire 23' to a contact 24which normally engages-a contact plate 25 on but insulatedfrom theknock-off or stopping lever l2 when the latter is in its normal runningor non-stopping position. A second contact 26 also engaging plate 25 isconnected by wire 2'5" to a relay 28 connected by wire 29 to the otherline Wire 26; This constitutes a detecting circuitwhicli is ordinarilyopen at the weft detector but'will be closed by simultane ous engagementof the two detector fingers l l and [8 with the ferrule 9, at whichtimethe'detecting circuit will be closed and the relay will be energized toefiectclosure of certain contacts and openingof other cont-actsassociated with it.

Because of thebriefness of closureof the detectorcircuitforreasonsalready described, particularly at hi h loom speeds, aholding circuit,

means is provided which bypassesor short cir cuits the weft detector.This circuit is asfollowsL line wire 28; wire 29, relay 23, wire 27,contact 26,

Under these conditions no. current cancontact plate 25, contact 24, wire30, contact 3|, contact plate 32, (controlled by the relay), contact 33,wire 34, and wire 2| back to the transformer T. This holding circuit ismaintained closed subsequent to the detecting period and after theferrule :53 moves rearwardly away from the detector due to lay motion,and so long as lever i2 is in running position.

The solenoid is energized by a condenser C which is normally connectedacross the lines 20 and 2! by the following charging circuit: wires 21and 35; contact 26, contact plate 3! (controlled by the relay), contact38, wire 39, rectifier 40, wire 4%, condenser C, and wire 42 to theother line wire. 20; The plate, 3'! electrically connect the contacts 36and33 when the relay 28 is deenergized so that the condenser C isnormally connected across the transformer and in a fully chargedcondition. When relay 28 is energized, however, the plate 3'! moves awayfrom the contacts 36 and 38 and opens or interrupts the chargingcircuit;-

The relay 23 alsocontrols the following solenoidor'condenser dischargecircuit: condenser C, wire 4|, wire t5, solenoid S, wire 46, contact 41,cont-act'plate 48 (controlled by the relay), contact 49,,wire 50, andwire42 back to the con: denser. This circuits is normally open butwhenthe rela 28 is energized to cause plate 48 to en,- gage contacts 4'? and49, the discharge circuit is closed and, the condenser dischargesthrough the solenoid to energize; it with resultant lifting of the link'IE. to its stopping position. The discharge circuit is connected to thecharging circuitat a point between the, rectifier and the, condenser;but opening of the charging circuit by movement of ,plate 3'! away'fromthe-contacts,

and 38- prevents currentgfrom the transformer,

from passing toth solenoid or through the discharge circuit, and thesolenoid willbeenergized tion,v to stopping position, one ofthe effectsof which is vto stop the loom and another effect of whichis to move,contact plate 25 away from.

contacts 24 and 26. This results in opening the holdingcircuit andcausing deenergizationof the relay 28. upon return from their indicatingposition shown in Fig. 2to their normalposition indicated in Fig. 1'.

From the foregoing it will'be seen that the detector system provides anormally charged condenser and, a normally open discharge circuitincluding a solenoid, together with means for,

closing the discharge circuitwhen the detector.

indicates weftexhaustion. The-solenoid'is associated with a part, suchas link l3, which is moved to controlling or knock-off position when thesolenoid is energized, and it is therefore not necessary to continueenergization of thesolenoid beyond the time required to lift the link13. The

condenser and solenoid have such electric char acteristics that thecondenser is ableto maintain thesolenoid energized for several cycles ofalter naLin-g current sufficiently long to perform its required work.The holdingcircuit will be-opened The contact plates 32, 3'! and there--when the knock-off lever I2 moves to stopping position, whereupon thecontacts controlled by the relay 28 return to their normal condition.While the switch including contacts 24 and 26 and the contact plate 25has been shown herein as being opened by knock-off lever l2, it isapparent that the'invention is not limited to a particular part forcontrolling the switch. If desired a break in one or the other of themain line wires 20 or 2| could be effected by the shipper mechanism whenmoving to stopping position, but this has not been illustrated, since itis well understood. It will further be seen that a very brief contactestablished by the weft detector and ferrule l9 will sufiice to set thedetector system into operation and that a considerable period of timecan elapse between indication of weft exhaustion by the detector and theultimate use which the loom makes of this indication, that use asspecifically set forth herein being loom stoppage. The invention,however, is not to be limited to loom stoppage, since it will suflice ifdischarge of the normally charged condenser through the solenoid effectssetting of some part of the loom to be followed by a change in loomoperation.

Having thus described the invention it will be seen that changes andmodifications of the foregoing specific disclosure may be made withoutdeparting from the spirit and scope of the invention.

What is claimed as new is:

1. In an electric weft detecting system for a loom having a source ofalternating current electric power, an electric weft detector andmechanism effective to cause a change in loom operation when a solenoidis energized, said system comprising a charging circuit including acondenser, a normally closed switch and a rectifier, a discharge circuitincluding the condenser, solenoid and a normally open switch connectedto the charging circuit between the rectifier and condenser, andelectric means effective upon indication of weft exhaustion by the weftdetector to open said normally closed switch to prevent flow of electriccurrent from said source through the rectifier to the solenoid and closesaid normally open switch to energize the solenoid by electric powerderived from the condenser only.

2. In an electric weft detecting system for a loom having a source ofelectric power, an electric weft detector and mechanism effective tocause a change in loom operation when a solenoid is energized, saidsystem comprising an electric detecting circuit including a normallydeenergized relay effective upon indication of weft exhaustion by thedetector to energize the relay, a holding electric circuit completedthrough the relay and source upon energization of the relay, a normallyclosed electric charging circuit including the source and a condenser, adischarge circuit normally open including the condenser and solenoid,electric means acting due to energization of the relay to open thecharging circuit and close the discharge circuit to cause energizationof the solenoid by electric power derived from the condenser, and meansacting subsequent to energization of the solenoid effective to open theholding circuit, whereupon the relay becomes deenergized, the chargingcircuit is closed and the discharge circuit is opened.

3. In an electric weft detecting system for a loom having a source ofelectric power, an electric weft detector which can indicate weftexhaustion at a given point only in the loom cycle and having mechanismeffective at a later point in the loom cycle to cause a change in loomoperation if a part thereof has previously been moved due toenergization of a solenoid, the systern comprising a normally openelectric detector circuit powered by said source and including thedetector and a relay and closed to energize the relay when the detectorindicates weft exhaustion at said given point in the loom cycle, anelectric chargingcircuit including an electric condenser normally closedto charge to condenser by power derived from said source, a normallyopen electric discharge circuit connected to the charging circuit andincluding the solenoid and condenser, and electric means effective uponenergization of the relay to close the discharge circuit to energize thesolenoid by power derived from the condenser and open the chargingcircuit prior to said later point in the loom cycle to the end that thesolenoid will be energized by power derived from the condenser only andmove said part and become deenergized prior to said later point in theloom cycle.

4. In an electric weft detecting system for a loom having a source ofelectric power, an electric weft detector and stopping mechanismnormally in non-stopping position but moving to stop the loom incidentto but subsequent to energization of a normally deenergized solenoid,the system comprising an electric detecting circuit powered by saidsource and including a relay and a switch normally closed when thestopping mechanism is in non-stopping position and closed to energizethe relay when the weft detector indicates weft exhaustion, a normallyopen holding electric circuit powered by said source including saidswitch and relay and closed as a result of energization of the relay, anormally closed charging electric circuit including an electriccondenser powered by said source to keep said condenser normallycharged, means opening said charging circuit as a result of energizationof the relay, and a normally open discharge electric circuit includingthe condenser and solenoid closed as a result of energization of therelay to energize the solenoid by the condenser only and independentlyof said source, movement of the stopping mechanism to stopping positiondue to energization of the solenoid opening said switch and holdingcircuit with resultant deenergization of the relay and closure of thecharging circuit and opening of the discharge circuit.

5. In an electric weft detecting system for a loom havinga source ofelectric power and an electric weft detector which is capable ofindicating weft exhaustion, the loom having a periodically rockingactuator lever, a knock-off lever, and a link operatively connected tothe knockoff lever normally out of operative position relatively to theactuator lever but moved into op erative position with respect to theactuator lever when a solenoid is energized, a holding detent operativeupon movement of the link to operative position with respect to theactuator lever to move to holding position to maintain said link in saidoperative position relative to the actuator lever, the system comprisinga normally open electric detector circuit powered by said source andincluding the detector and a relay closed to energize the relay when thedetector indicates weft exhaustion, an electric charging circuitincluding an electric condenser normally closed to charge the condenserby power derived from said source, a normally open electric dischargecircuit connected to the charging circuit and in- 7 8 cluding thesolenoid and condenser, and electric REFERENCES CITED means effectiveupon energization of the relay to The following references are of recordin the close the dischaIC-Ige circufit to irl lergiize'tthe soleme ofthis patent; noid by power erived' rom e eec ric condenser a sufiicientlength of time to enable said 5 UNITED STATES PATENTS holding detent tomove to the holding position Number Name Date thereof relative to thelink, said holding detent 2,086,913 'Kelly Mar. 14, 1931 remaining. inthe holding position thereof sub- 2,429,530 Sepavich et al. Oct. 21,1947 sequent to complete discharge of the condenser to maintain saidlink in the path of said actuator 10 lever.

VICTOR F. SEPAVICH.

